Acid resistant and metal adherent compositions of matter and method of making same



Patented June 7, 1938 2,119,522 ACID RESISTANT AND METAL ADHERENT COMPOSITIONS OF MATTER AND METH- OD OF MAKING SAME Lawrence C. Brunstrum, Chicago, and Frederick H. MacLaren, Calumet City, 11]., assignors to Standard Oil Company. Chicago, 11]., a corporation of Indiana No Drawing. Application April 30, 1934, Serial No. 723.164

8 Claims.

This invention relates to new and improved compositions of matter for use in lubricating plug valves and for other purposes.

It is an object of our invention to provide a method of lubricating plug valves by the use of a lubricant which has a very high degree of resistance to acids and which adheres tenaciously to metal. It is another object of our invention to provide a lubricant which will make possible this method of lubrication. A further object is to provide new compositions of matter useful for this purpose and for other purposes, for instance, for use as slushing compounds. Still further objects of our invention will become apparent as the description thereof proceeds.

Many attempts have been made in the past to provide lubricants suitable for use on plug valves in acid service, but prior to our invention no completely satisfactory lubricant for this pur pose had beendeveloped. Such a lubricant must have many necessary, or at least highly desirable.

properties. Amongst these, is the necessity of a good body which will permit the lubricantto be pressed into a stick which will be sufficiently firm and solid at normal atmospheric temperatures to retain its shape and which will at the same time be sufiiciently plastic to flow into the space between the cock and body of a plug valve. The lubricant must necessarily have a true grease structure and cannot be a mere soap-thickened oil. -A still more necessary property is acid resistance, since when lubricating a plug valve used in acid service it is highly essential that the acids do not attack the lubricant, thereby removing it or injuring its properties as a lubricant. Possibly the most important property of all, however. and certainly the most difficult to'obtaln consistently with the other necessary properties, is a high degree of adhesiveness to metal. At the same time the product must be a good lubricant and must not, cause the valve to stick.

With plug valve lubricants of the prior art it has been found that when minute pin holes are present in the' lubricant film, as is almost invariably the case, the acid will penetrate to the metal, generate hydrogen and/or other gases and thereby lift the surrounding lubricant from the metal. This action takes place progressively. until ultimately all of the lubricant has been removed. With the lubricants of our invention no such action occurs. The lubricant is so adhesive that it does not lift from the metal even when subjected to a considerable degree of hydrogen.

evolution from surrounding bare metal. As an example of this, lubricants made in accordance with our invention have been compared with other lubricants by the following method:

A sheet of iron or other metal is coated on both sides over one-half of its surface with the lubricant to be tested and the sheet is then immersed 5 in a bath of strong mineral acid. With either sulfuric acid or hydrochloric acid the best lubricants of the prior art will be removed rather rapidly either by direct attack of the acid on the lubricant or by the hydrogen lifting" heretofore referred to. With the lubricants of our invention, this does not occur. In the caseof sulfuric acid, the portion of the metal sheet which is uncoated is removed and the coated portion remains intact, being fully protected by the lubricant. In the ease of hydrochloric acid, which acts somewhat more vigorously than sulfuric, the uncoated half of the metal sheet is eaten away and then the coated half is very gradually eaten away from the inside out. In other words, the acid works upwards from the edge of the metal left bare by the removal of the uncoated portion of the metal, but the lubricant is so extremely tenacious that the exterior surfaces of the coated portion of the metal are completely protected even under these extremely vigorous conditions. In spite of this extreme tenacity to metals the compositions which We have invented are excellent lubricants and do not cause the valves in which they are used to stick.

The essential ingredient of the lubricants which we find will accomplish this purpose are condensation products similar to those obtained by the condensation of materials such as chlorinated paraffin wax with aromatic hydrocarbons. for in- 3 stance naphthalene, by the use of catalysts, such. as aluminum chloride. Compounds of this type, as made by the processes of one of the present inventors or by similar processes. are known as Pourex" and are described in U. S. Patents Nos. 1.963.917 and 1.963.918. issued to Frederick H. MacLaren, which were copending with the present application. In most respects. the precise raw materials and manufacturing process used in making the Pourex" are not important and condensation products of the type mentioned are highly useful generally as lubricants or constituents of lubricants for use in plug valves, particularly when the plug valve is to be subjected to acid service. Nevertheless. there is one particular in which a variation of the manufacturing process, as heretofore used, gives highly improved results. ,It has been customary in the manufacture of Pourex" to use a chlorinated wax containing from about 10% to about 18%, for intemperatures in relatively thin layers.

stance, about 15% by weight of chlorine. Such a chlorinated wax when condensed with naphthalene produces a Pourex having highly desirable properties as a pour point depressor, as a dewaxing aid, etc. It does not, however, give the best results in the compositions of the present invention. We find on the other hand, that if the chlorinated wax is fractionated, for instance, by vacuum distillation, fractional crystallization from solvents, or sweatin so as to produce two fractions, and if they are separately condensed with naphthalene, two types of Pourex are produced, one of which is a highly vis cous but fluid material and the other is a plastic and extremely adhesive material which is practically solid at room temperatures. This latter grade of Pourex is highly superior for use as a plug valve lubricant or other metal-adherent composition or as a constituent thereof. It is made from the harder, higher melting point fraction of the chlorinated paraffin wax.

As an example of the manufacture of this improved type of Pourex, a'chlorinated wax containing about 15% of chlorine was. subjected to gradual heating from below to slightly above room It was found that an oily material sweated out from thechlorinated wax and could be removed. When about one-half of this material has been removed the sweating was stopped and the two and the cake, were separately condensed with naphthalene in the presence of aluminum chloride to make Pourex as described in the aforementioned co-pending patents. The Pourex made from the chlorinated wa'x cake was found to be highly superior, for present purposes, to that made from the chlorinated wax drips. Instead of separating the original chlorinated wax into' approximately equal fractions, any desired degree of fractionation can be obtained by any of the means aforementioned. We believe that the important feature is that the chlorinated wax to be used to produce the desired type of Pourex. should be a hard, low chlorine content material. The chlorine contentv should, for in.-

stance, preferably be from about 2% to about 6% by weight. Instead of fractionating a chlorinated wax of higher chlorine content it is possible to reach somewhat the same result by directly chlorinating the paraifin wax to the desired extent. 1. e., for instance, to a chlorine content of from about 2% to about 6% by. weight, but this is not preferred. The paraffin wax used for the chlorination should preferably be a relatively high melting point wax, for instance onehaving a melting point above about 130 F. and preferably above about 135 F.

Pourex, particularly the type of 'Pourex made from the low chlorine fraction of paraflin wax, can be pressed into sticks and applied in this'form or otherwise to a plug valve giving lubrication superior to that obtainable with prior art lubricants, particularly in the case of plug valves used in acid service. This is not true to anywhere near the same extent of the ordinary melting or softening point above the tempera- For one thing, Pourex is relatively expensive.

For another thing, it is difficult to meet the requisite specifications and there are other-disadvantages. We have found that these disadvantages can'be overcome by blending various other materials with the Pourex.' We prefer to add oil or wax, or preferably both oil and wax. It is highly desirable that the oil and/or wax used should have a very high degree of acid resistance. We prefer to use a mineral lubricating oil which has been strongly treated with sulfuric acid, preferably an oil of the type known as white oil. Thus, for instance, we 'can use an oil of which not more than about and preferably not more than about 1% will be soluble in an excess of 95% sulfuric acid at room temperatures. As a wax, we prefer to use a refined grade of petroleum wax, for instance, one having melting point of at least about 125 F. Beeswax is a satisfactory substitute for the "paraffin wax and other waxes such as ozokerite, Montan wax, etc. can be used. High melting pointparaiiin waxes and petroleum waxes in general are satisfactory but we prefer to use a refined grade of very high melting point petrolatum wax known to about of oil and from about 5% to about 40% of wax. Preferably there should be at least one-third as much wax as oil since otherwise it is difficult or impossible to obtain the desired grease-like body and other properties described above. It will be realized that these various proportions are only approximate and are subject to considerable variation. Thus, for instance, if the Pourex used is very soft and fluid a higher percentage of wax is desirable in order to obtain the properties previously mentioned. Similarly, if the viscosity of the oil is low a higher amount of wax can be'used than in the case of a high viscosity oil. The various ingreclients can be incorporated together by heating and agitating them, for instance, in a conventional grease kettle.

Another ingredient which we find highly desirable, but by no means necessary in our compositions, is unreacted chlorinated wax. This chlorinated wax should preferably have a chlorine content of from about 5% to about 15% by Weight. In body it is intermediate between wax and oil and therefore can be used to replace a portion of the wax and oil used in the compositions mentioned in the last paragraph. I

It is, however, preferable to the wax and oil thus replaced since it is more adhesive to metals. The percentage of oil and wax replaced by ,the

chlorinated wax depends somewhat on the relative bodies of the oil, wax and chlorinated wax.

Suitable compositions can be made from Pourex and chlorinated wax alone. Such compo- 2,119,522 sitions may range from about 10% Pourex and 90% chlorinated wax toabout 98% Pourex .and about 2% chlorinated wax. Preferably, however, the chlorinated wax should not entirely replace the oil and wax but should be present. as a fourth constituent. Thus, for example, from about 8% to about 40% Pourex, from about 10% to about oil and from about 5% to about 50% of wax and any amount of chlorinated wax up to about 50% or 60% can be used. Higher percentages of Pourex can be used if economically feasible. One lubricant which we have found very satisfactory is composed of Ezwmple I Percent Pourex; 10 White oil having a viscosity of about '75 at 100F s 10 Chlorinated wax 40 White Superla wax 40 We find that still better results can be obtained by incorporating in any of the above compositions a small amount of very finely divided asbestos, such as air-floated asbestos. Quantities of, for instance, from about 1% to about 50% by weight, and preferably from about 20% to about 35% by weight of the total composition can be used, the other materials being present in the relative proportions previously indicated. The presence of this very finely divided asbestos gives the finished lubricant bulk and structure, makes it easier to press and gives a stick lubricant. It also acts as a stiffening agent and therefore can be used to reduce the amount of wax otherwise necessary. The asbestos is, of course, acid resistant and does not impair 'this characteristic of the lubricants. Another highly important feature which the asbestos produces inthis type of lubricant is that it gives a body which is not affected by temperature. Lubricants made in accordance with our invention and containing, say. about 25% of air-floated asbestos remain thick at temperatures at least up to 300 F. and in fact up to the temperatures at which charring commences. When using asbestos it is important that the oil, if any, used in the composition, be a high viscosity oil, preferably one having a viscos- .ity above about 150 seconds Saybolt at 100 F.

and preferably above about 250 seconds Saybolt at 100 F. When asbestos is not used low-viscosity lubricating oils are satisfactory.

Two of the lubricants which we have found most satisfactory and the permissible and preferred ranges of constituents for a plug valve lubricant of this type are as follows:

As previously pointed out, the relative amounts of the various constituents used will vary with the properties of the various constituents and the results which it is desired to obtain. Other constituents can be added without departing from the invention.

Although the compositions of matter set forth above are particularly useful for the lubrication ofplug valves in general, and most particularly the lubrication of plug valves used in acid service, their properties of acid resistance and extreme tenacity of adhesion to metals are important in other applications and particularly for use in protecting metals from corrosive liquids and gases, i. e. as slushing compounds. For this use a material slightly more fluid than that desirable as a plug valve lubricant is usually desirable and the wax in the above compositions can sometimes be completely eliminated. Thus, a mixture of from about 10% to about 60% Pourex and from about 40% to about 90% acid resistant mineral oil can be used. The compositions 'set forth above using Pourex, oil and wax and the compositions containing chlorinated wax are also suitable for this purpose.

Percentages as given herein are on a weight basis.

While we have described .our invention in connection with certain specific embodiments thereof and in connection with certain theories of opera.- tion, it will be understood that these are by illustration only and not by way of limitation.

We claim:

1. A method of manufacturing a metal-adherent acid resistant composition of matter comprising iractionating a chlorinated paraffin wax into a high melting point fraction and a low melting point fraction and then condensing said high melting point fraction with an aromatic hydrocarbon.

2. An acid resistant, grease-like, metal adherent plug valve lubricant comprising the following ingredients in about the following percentages by weight:

Percent Condensation product of an aromatic hydrocarbon and a chlorinated wax 10-40 Acid-resistant mineral lubricating oil 5-40 Refined wax 5-40 Air-floated asbestos 5-40 valve lubricant having a softening point above about 130 F. and an A. S. T. M. penetration within the range from about 25 to about '70, comprising a condensation product of an aromatic hydrocarbon and a high melting point chlorinated wax fraction having a chlorine content ranging from about 2% to about 6% from which low melting point constituents have been eliminated.

6. A plastic, acid-reslstant,- grease-like plug valve lubricant having a softening point above about 130 F. and an A. S. T. M. penetration within the range from about 25 to about 70, comprising a condensation product of an aromatic hydrocarbon and a chlorinated wax. said chlorinated wax containing from about 2% to about 6% of chlorine by weight.

'1. An anti-rust composition containing a condensation product of an aromatic hydrocarbon and a high melting point chlorinated wax fracnon having a. chlorine content ranging from 2% to about 6% from which low melting point constituents have been eliminated, said condensation product having a softening point above about 130 F. and an A. S. T. M. penetration within the range from about 25 to about '70.

8. An anti-rust composition containing a condensation product of an aromatic hydrocarbon, 

